1. Technical Field
The invention relates to photonic devices. In particular, the invention relates to optical microring resonators.
2. Description of Related Art
Microring resonators are becoming popular components for use in many modern photonic devices. For example, a silicon microring may provide a CMOS-compatible means for implementing an optical filter, an electro-optical modulator, a laser, and even a detector (although some of these implementations may require that one or more of carrier injection, optical gain or optical absorption mechanisms be incorporated into the microring resonator). The popularity of microring resonators is due in large part to their relatively small size, potentially high quality factor (Q), transparency to off-resonance light, and near lack of intrinsic reflection. While microring resonators, which provide the functionality of a ring resonator in a much more compact size, may lead to many beneficial characteristics (e.g., higher integration density and wide free spectral range), microring resonators that are both critically coupled and that provide sufficiently high Q have proved relatively difficult to achieve in practice. Such a microring resonator would satisfy a long felt need.